Decellularized Porcine Corneas Have Been Successfully Used in Human Corneal Transplantation
Yes, decellularized porcine corneas have been successfully used in humans for corneal treatment, specifically as anterior lamellar keratoplasty grafts to treat corneal ulcers in patients in China. 1
Current Status of Porcine Corneal Xenotransplantation in Humans
The use of decellularized porcine corneas represents a significant advancement in addressing the global shortage of human corneal tissue for transplantation. According to the International Journal of Surgery, a Chinese research group has achieved encouraging clinical results using decellularized porcine corneas as anterior lamellar keratoplasty (ALK) grafts to treat corneal ulcers in human patients 1.
Advantages of Decellularized Porcine Corneas
Decellularization offers several important benefits for xenotransplantation:
- Reduced immunogenicity: Removal of cellular components significantly reduces the immune response compared to fresh corneas 1
- Preservation of extracellular matrix structure: The decellularization process can maintain the essential collagen architecture needed for corneal function 2
- Abundant supply: Porcine corneas could help solve the worldwide shortage of donor corneal tissue
Decellularization Methods
Multiple techniques have been developed to decellularize porcine corneas, though no standardized protocol has yet been established 3. The most common methods include:
- Hypertonic saline-based decellularization: Shown to maintain intact collagen structures while removing cellular components 2
- Chemical methods: Using agents like sodium dodecyl sulfate (SDS), triton X-100, or EDTA 4
- Physical methods: Including freeze-thaw cycles, high hydrostatic pressure, or nitrogen gas 3
- Combined approaches: Often more effective than single methods alone 3
The hypertonic saline method has demonstrated particularly promising results, with xenografts remaining clear in animal models for over 6 months 2.
Clinical Applications and Outcomes
The clinical use of decellularized porcine corneas has primarily focused on anterior lamellar keratoplasty, where only the front portion of the cornea is replaced. This approach is particularly suitable for treating:
- Corneal ulcers
- Anterior stromal opacities
- Certain types of corneal dystrophies
The biophysical properties of porcine corneas make them suitable alternatives to human tissue:
- Corneal power: Porcine corneas (40D) are slightly flatter than human corneas (44D), but within a tolerable range for transplantation 1
- Tensile strength: Similar to human corneas, though with some differences in stress-relaxation and stiffness 1
Future Perspectives
The field of corneal xenotransplantation continues to evolve with several promising approaches:
Further refinement of decellularization techniques: To optimize the balance between complete cell removal and preservation of corneal architecture 3
Recellularization with human cells: Some research explores repopulating decellularized porcine corneas with human corneal cells to create hybrid grafts 4, 5
Genetically engineered pigs: Development of GTKO/CD46/CIITA-DN pigs could further reduce human immune responses 1
Potential Limitations and Considerations
Despite promising results, several challenges remain:
- Potential for corneal haze or scarring: Post-transplant complications have been observed in some cases 5
- Variability in outcomes: Results may depend on specific decellularization protocols and patient factors
- Long-term durability: More extended follow-up studies are needed to assess long-term outcomes
With continued advances in immunosuppressive protocols, decellularized porcine corneas represent a realistic option for addressing the global shortage of corneal tissue for transplantation 1.